The present invention relates generally to processes that demodulate received transmissions. More specifically, the invention relates to a system and method of demodulation which requires reduced complexity over conventional systems.
Conventionally, data communications systems, either voice or non-voice, make use of signal diversity or redundancy when transmitting information to provide an improvement in performance without comprising certain other aspects of the data transmissions system. Two conventional techniques which are used that add time diversity are known as interleaving and forward-error correcting (FEC) coding.
When using FEC coding, the demodulator often needs to provide a soft decision that approximates the probability or the logarithm of the probability that a given symbol or bit was transmitted. This is especially important when the receiver employs iterative decoding and demodulation.
In certain cases, it is advantageous that the receiver not be required to estimate the phase of the received carrier. In such a case, the demodulator is designed subject to the constraint that the phase is unknown. Such demodulators are said to be non-coherent.
In certain situations it may be desirable to demodulate received signals in a less complex manner. Accordingly, there is a need for a system and method in which a received symbol sequence is broken up into subsequences for demodulation.
It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.